One device contained in the prior art comprises a body with an air inlet and corona-forming and precipitation electrodes of opposite polarities. An electrostatic precipitation element is installed near the precipitation electrodes. The electrostatic precipitation element comprises two metal nets with precipitating fabric set in-between (for ref. see Inventor's Certificate of the USSR No. 921629, class B 03 C 3/08).
The above-mentioned known device does not avoid extraction of harmful positively charged aeroions. Additionally, the system does not provide for saturation of cleaned air with molecules of aromatic or medical substances if necessary.
As to its principle of operation, the proposed device is closest to a device described in the Patent of Russian Federation No. 2159683, class B C 3/04 published in 2000. This known device comprises a body with an air inlet. Located inside the body are corona-forming and precipitation electrodes with opposite polarities, passive electrodes are set, behind electrodes an electrode—generator of negative electrodes being electrically coupled with precipitation electrodes and a vessel with aroma or medical substances are mounted.
The principle upon which the prior art device is based is the forming of charged particles in the field of corona-forming charge appearing between positively charged corona and negatively charged precipitation electrodes. Corona-forming and deflecting electrodes have similar polarities but different electrical potential in relation to precipitation electrodes. The presence of deflection electrodes increases level of purification of air greatly (up to 95-99 percent). Passive electrode acquiring positive charge prevents positively charged aeroions from leaving air cleaner thus preventing an environment from being polluted with harmful positively charged aeroions. Said air cleaner provides for the forming of negatively charged aeroions of oxygen in great quantities. A portion of these ions are seized by dust or aerosol particles and then fall on passive electrodes thus covering electrodes with a dielectric fine dispersion layer. This layer of dust partially neutralizes positively charged electrodes but mainly decreases the efficiency of the passive electrode as a precipitator of positively charged aeroions. Therefore, it becomes necessary to clean the passive electrodes, thus creating additional work and inconvenience.
The use of a vessel allows saturation of the air with aromatic substances; however, liquid overflowing from the vessel is mixed with dust which has fallen. This situation makes the inner surfaces dirty, worsens electric isolation, safety and may produce electrical failure. Likewise, the intensity of liquid evaporation in a non-homogeneous electric field is relatively great, small amounts of liquid are evaporated very fast. This requires frequent refilling of the vessel with aromatic or medical liquids. As the vessel is mounted inside the air cleaner, such recharges are connected, as a rule, with partial or full reassembling of the device which leads to additional time and inconvenience. High aerodynamic resistance also reduces efficiency of the device.